A fully closed crankcase ventilation system is installed on all modern vehicles having internal combustion engines. A positive crankcase ventilation valve (PCV) is installed for example on the cylinder head cover of the vehicle and an outlet from the valve is connected to manifold vacuum. A crankcase inlet hose is generally connected to the cylinder head cover from the vehicles air cleaner whereby air is circulated through the engine and drawn out of the cylinder head cover by manifold vacuum into the combustion chambers and expelled with the exhaust gas.
It is a principle object of the present invention to provide a valve that is adjustable and the adjustment regulates the proportion of air to crankcase gases which are drawn by manifold vacuum to the base of the carburetor.
It is also an object of the present invention to connect the low pressure side of the improved valve to the vacuum regulator on the distributor to regulate the firing time of the engine.
It is desirable to have the air-gas mixture in the engine cylinders to fire at maximum compression that is top dead center during the compression stroke. Since timing for ignition varies with the engine RPMs it is necessary to have automatic means to advance firing as engine speeds increase and to retard firing at low idle speeds. In general at low speeds firing occurs from about 4.degree. to about 12.degree. to top dead center and at high speeds the distributor is advanced to for example 30.degree. to 40.degree. earlier than top dead center.